# NTSB ANC16IA013: Robinson Helicopter R44 II, N395CE, Anchorage, AK, January 7, 2016 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: January 7, 2016, 11:00 local (20:00 UTC) - Place: Anchorage, AK - Coordinates: 61.174167, -149.998062 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.1742&lon=-149.9981&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report December 12, 2016 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: Precision Airmotive LLC, Federal Aviation Administration - NTSB case key (mKey): 92562 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC16IA013 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/92562/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=92562 - Page: https://openairdocs.org/ntsb/ANC16IA013 ## Probable cause The overhaul facility's improper and excessive use of an approved lubricant during overhaul of the fuel injection servo, which resulted in a disruption of fuel flow and a total loss of engine power. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine fuel and control: fuel distribution](https://openairdocs.org/ntsb-findings/01057310): Aircraft › Aircraft power plant · Incorrect service/maintenance (probable cause); cases with it: [Robinson Helicopter R44 II, 2 cases](https://openairdocs.org/ntsb-findings/01057310/cases.md?model=7640122), [All aircraft, 55 cases](https://openairdocs.org/ntsb-findings/01057310/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Robinson Helicopter R44 II, 20 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=7640122), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) ## Analysis The flight instructor reported that the purpose of the flight was to do a postmaintenance check flight after servicing and overhaul of the helicopter's fuel injection servo assembly. The instructor stated that, after an extensive preflight inspection was completed, the helicopter was moved outside the hangar. The helicopter's engine was started and allowed to warm up for about 10 minutes, and all ground run-up checks were satisfactory. While operating at 100 percent rotor rpm and while raising the collective to begin the takeoff, the engine abruptly experienced a total loss of power.The helicopter remained on the ground and did not sustain damage. A detailed examination, which included disassembly of the fuel injection servo, revealed white contamination ranging in consistency from grease-like to solid throughout the entire fuel servo assembly. The lubricant was used in excess and in locations not approved by the manufacturer's maintenance manual. It is likely that the contamination throughout the fuel injection servo caused a disruption in fuel flow, which resulted in a total loss of engine power. ## Factual narrative On January 7, 2016, about 1100 Alaska standard time, a Robinson R44 II helicopter, N395CE, sustained a total loss of engine power just prior to departure at the Anchorage International Airport, Anchorage, Alaska. The private pilot, who was the helicopter owner, and his flight instructor were not injured. The helicopter sustained no damage as a result of the incident. The helicopter was registered to, and operated by, Airglas, Inc., under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan had been filed. During an on-scene interview with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on January 7, the flight instructor reported that the purpose of the flight was to do a post maintenance check flight after servicing and overhaul of the helicopter's fuel injection servo assembly. The instructor stated that after an extensive preflight inspection was completed, the helicopter was moved outside of the hangar. The helicopter's engine was started and allowed to warm up for about 10 minutes, and all ground run-up checks were satisfactory. He said that while operating at 100 percent rotor rpm and while raising the collective to begin the takeoff, the engine abruptly lost all power. The helicopter was equipped with a fuel injected, Lycoming IO-540 series engine. A postincident inspection of the fuel servo assembly revealed a white, greasy substance within the venturi of the servo assembly. The helicopter's maintenance records revealed that the fuel injection servo had been overhauled on December 14, 2015 by Alaskan Aircraft Engines, Inc., Anchorage, before being reinstalled on the accident helicopter. On January 14, the NTSB IIC along with another NTSB investigator, and a representative from Precision Airmotive LLC, examined the fuel injection servo at the facilities of Precision Airmotive in Marysville, Washington. Due to excessive white grease like contamination behind the test port plugs the servo was not flow tested. Disassembly inspection revealed large amounts of white contamination ranging in consistency from grease like to solid. The contamination was present in the manual mixture control valve, idle valve plate, fuel section O-rings, and the fuel diaphragm with the bleed port almost completely blocked. On January 19, the NTSB IIC along with another NTSB investigator, and two FAA aviation safety inspectors, visited the facilities of Alaska Aircraft Engines, Inc., in Anchorage, and disassembled a recently overhauled fuel injection servo. The inspection revealed excessive amounts of a white grease like substance throughout the fuel injection servo, consistent with the servo removed from the accident helicopter. A representative from Alaska Aircraft Engines stated that about 6 months prior they had switched assembly lubricants to Dupont Krytox an approved lubricant, but due to the investigation realized it was not being used in accordance with themaintenance manual and ended in excessive and inappropriate application. Dupont describes Krytox 240 series greases in part: as white, buttery greases based on perfluoropolyether (PFPE) oils. These synthetic fluorinated lubricants are used in extreme conditions such as continuous high temperatures up to 300°C (572°F) and higher temperatures for shorter periods, depending on product grade limits. Chemically inert and safe for use around hazardous chemicals, these lubricants are nonflammable and are safe for use in oxygen service. A review of the Precision Airmotive Corporation Aircraft Fuel Injection Maintenance Manual for the RSA-10-AD1 Fuel Injection Servo Assembly lists three places where Krytox is to be used during assembly and states, in part: "Apply Krytox or Braycote on mixture control lever assembly between lever stop and preformed packing. NOTE: Remove excess Braycote or Krytox with Fluoroclean X-100. Apply Krytox or Braycote on idle valve shaft outboard preformed packing NOTE: Remove excess Braycote or Krytox with Fluoroclean X-100. Place servo stem spring over stem of fuel diaphragm assembly Lubricate threaded portion of diaphragm with ASTM Number 5 or Vaseline. Apply a light film of Krytox or Braycote to the concave side of seal. Place servo stem seal over stem with flange and concave side up. Press seal down on diaphragm stem to engage it at the spring. Remove lubricant from stem." In a conversation with the NTSB IIC, a representative from Precision Airmotive LLC stated that Krytox should be applied in a thin light coat, with all excess removed in only the locations specified in the maintenance manual. On January 19, Alaska Aircraft Engines issued a Service Advisory that stated, in part: "Beginning in June of 2015 Alaskan Aircraft Engines purchased and began use of an approved assembly lube it had not used previously. This lube was used in excess and in locations not required by the manufacturer's service manual. We believe this has the potential to cause a fuel distribution problem." ## Aircraft - Registration: [N395CE](https://openairdocs.org/aircraft/N395CE), registered now, S/N 11647, built 2007 (OpenAirDocs) - Reported make and model: ROBINSON HELICOPTER COMPANY R44 II - Registry model: [Robinson Helicopter R44 II](https://openairdocs.org/model/robinson-helicopter-r44-ii) (registry code 7640122) (OpenAirDocs) - Registry engine: [Lycoming IO-540-AE1A5](https://openairdocs.org/engine/lycoming-io-540-ae1a5) (registry code 41899, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 11647 - Year built: 2007 - Engines: LYCOMING IO-540-AE1A5 reciprocating - Damage: No damage - Flight: Instructional, Part 91 - Airworthiness certificate: Standard, Normal - Departed: ANC, Anchorage, AK - Destination: ANC, Anchorage, AK - Airport: ANC, Ted Stevens Anchorage Intl ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 47; injuries: none; private; airplane ratings: single-engine sea, single-engine land; medical: class 3, with waivers/limitations; last flight review March 23, 2015; seat: right; restraint: 4-point; flight hours: 1,386.4 total, 162.6 in this make and model, 1,261.9 as pilot in command - Flight instructor; age 58; injuries: none; commercial, flight instructor; airplane ratings: single-engine land, single-engine sea, multi-engine land; instrument ratings: helicopter, airplane; medical: class 2, with waivers/limitations; last flight review March 23, 2015; seat: left; restraint: 4-point; flight hours: 5,000 total ## Weather - Conditions: Visual (VMC), Day - Wind: 10° at 6 knots - Visibility: 10 statute miles - Temperature: 19 °F, dew point 16 °F - Altimeter: 29.87 inHg ## Docket (4 files) The files NTSB released with the investigation on October 12, 2016, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=92562. 7.3 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40445284&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Alaska Aircraft Engines Inc. - Service Advisory (item 2, .PDF, 210 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40445285&FileExtension=.PDF&FileName=Alaska%20Aircraft%20Engines%20Inc.%20-%20Service%20Advisory-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 3, .PDF, 109 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40445286&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Master.PDF - Photo Array (item 4, .PDF, 4.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40445287&FileExtension=.PDF&FileName=Photo%20Array-Master.PDF From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.